Detection of fossil fuel emission trends in the presence of natural carbon cycle variability

Atmospheric CO _2 observations have the potential to monitor regional fossil fuel emission (FFCO _2 ) changes to support carbon mitigation efforts such as the Paris Accord, but they must contend with the confounding impacts of the natural carbon cycle. Here, we quantify trend detection time and magn...

Full description

Bibliographic Details
Main Authors: Yi Yin, Kevin Bowman, A Anthony Bloom, John Worden
Format: Article
Language:English
Published: IOP Publishing 2019-01-01
Series:Environmental Research Letters
Subjects:
Online Access:https://doi.org/10.1088/1748-9326/ab2dd7
_version_ 1797748001130676224
author Yi Yin
Kevin Bowman
A Anthony Bloom
John Worden
author_facet Yi Yin
Kevin Bowman
A Anthony Bloom
John Worden
author_sort Yi Yin
collection DOAJ
description Atmospheric CO _2 observations have the potential to monitor regional fossil fuel emission (FFCO _2 ) changes to support carbon mitigation efforts such as the Paris Accord, but they must contend with the confounding impacts of the natural carbon cycle. Here, we quantify trend detection time and magnitude in gridded total CO _2 fluxes—the sum of FFCO _2 and natural carbon fluxes—under an idealized assumption that monthly total CO _2 fluxes can be perfectly resolved at a 2°×2° resolution. Using Coupled Model Intercomparison Project 5 (CMIP5) ‘business-as-usual’ emission scenarios to represent FFCO _2 and simulated net biome exchange (NBE) to represent natural carbon fluxes, we find that trend detection time for the total CO _2 fluxes at such a resolution has a median of 10 years across the globe, with significant spatial variability depending on FFCO _2 magnitude and NBE variability. Differences between trends in the total CO _2 fluxes and the underlying FFCO _2 component highlight the role of natural carbon cycle variability in modulating regional detection of FFCO _2 emission trends using CO _2 observations alone, particularly in the tropics and subtropics where mega-cities with large populations are developing rapidly. Using CO _2 estimates alone at such a spatiotemporal resolution can only quantify fossil fuel trends in a few places—mostly limited to arid regions. For instance, in the Middle East, FFCO _2 can explain more than 75% of the total CO _2 trends in ∼70% of the grids, but only ∼20% of grids in China can meet such criteria. Only a third of the 25 megacities we analyze here show total CO _2 trends that are primarily explained (>75%) by FFCO _2 . Our analysis provides a theoretical baseline at a global scale for the design of regional FFCO _2 monitoring networks and underscores the importance of estimating biospheric interannual variability to improve the accuracy of FFCO _2 trend monitoring. We envision that this can be achieved with a fully integrated carbon cycle assimilation system with explicit constraints on FFCO _2 and NBE, respectively.
first_indexed 2024-03-12T15:58:40Z
format Article
id doaj.art-790b0c4245f9495c900bd141ad8e064e
institution Directory Open Access Journal
issn 1748-9326
language English
last_indexed 2024-03-12T15:58:40Z
publishDate 2019-01-01
publisher IOP Publishing
record_format Article
series Environmental Research Letters
spelling doaj.art-790b0c4245f9495c900bd141ad8e064e2023-08-09T14:44:30ZengIOP PublishingEnvironmental Research Letters1748-93262019-01-0114808405010.1088/1748-9326/ab2dd7Detection of fossil fuel emission trends in the presence of natural carbon cycle variabilityYi Yin0https://orcid.org/0000-0003-4750-4997Kevin Bowman1https://orcid.org/0000-0002-8659-1117A Anthony Bloom2John Worden3Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States of America; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States of AmericaJet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States of America; Joint Institute for Regional Earth System Science and Engineering, University of California, Los Angeles, CA, United States of AmericaJet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States of AmericaJet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States of AmericaAtmospheric CO _2 observations have the potential to monitor regional fossil fuel emission (FFCO _2 ) changes to support carbon mitigation efforts such as the Paris Accord, but they must contend with the confounding impacts of the natural carbon cycle. Here, we quantify trend detection time and magnitude in gridded total CO _2 fluxes—the sum of FFCO _2 and natural carbon fluxes—under an idealized assumption that monthly total CO _2 fluxes can be perfectly resolved at a 2°×2° resolution. Using Coupled Model Intercomparison Project 5 (CMIP5) ‘business-as-usual’ emission scenarios to represent FFCO _2 and simulated net biome exchange (NBE) to represent natural carbon fluxes, we find that trend detection time for the total CO _2 fluxes at such a resolution has a median of 10 years across the globe, with significant spatial variability depending on FFCO _2 magnitude and NBE variability. Differences between trends in the total CO _2 fluxes and the underlying FFCO _2 component highlight the role of natural carbon cycle variability in modulating regional detection of FFCO _2 emission trends using CO _2 observations alone, particularly in the tropics and subtropics where mega-cities with large populations are developing rapidly. Using CO _2 estimates alone at such a spatiotemporal resolution can only quantify fossil fuel trends in a few places—mostly limited to arid regions. For instance, in the Middle East, FFCO _2 can explain more than 75% of the total CO _2 trends in ∼70% of the grids, but only ∼20% of grids in China can meet such criteria. Only a third of the 25 megacities we analyze here show total CO _2 trends that are primarily explained (>75%) by FFCO _2 . Our analysis provides a theoretical baseline at a global scale for the design of regional FFCO _2 monitoring networks and underscores the importance of estimating biospheric interannual variability to improve the accuracy of FFCO _2 trend monitoring. We envision that this can be achieved with a fully integrated carbon cycle assimilation system with explicit constraints on FFCO _2 and NBE, respectively.https://doi.org/10.1088/1748-9326/ab2dd7fossil fuel emissionstrend detectionCO2 monitorcarbon cycle
spellingShingle Yi Yin
Kevin Bowman
A Anthony Bloom
John Worden
Detection of fossil fuel emission trends in the presence of natural carbon cycle variability
Environmental Research Letters
fossil fuel emissions
trend detection
CO2 monitor
carbon cycle
title Detection of fossil fuel emission trends in the presence of natural carbon cycle variability
title_full Detection of fossil fuel emission trends in the presence of natural carbon cycle variability
title_fullStr Detection of fossil fuel emission trends in the presence of natural carbon cycle variability
title_full_unstemmed Detection of fossil fuel emission trends in the presence of natural carbon cycle variability
title_short Detection of fossil fuel emission trends in the presence of natural carbon cycle variability
title_sort detection of fossil fuel emission trends in the presence of natural carbon cycle variability
topic fossil fuel emissions
trend detection
CO2 monitor
carbon cycle
url https://doi.org/10.1088/1748-9326/ab2dd7
work_keys_str_mv AT yiyin detectionoffossilfuelemissiontrendsinthepresenceofnaturalcarboncyclevariability
AT kevinbowman detectionoffossilfuelemissiontrendsinthepresenceofnaturalcarboncyclevariability
AT aanthonybloom detectionoffossilfuelemissiontrendsinthepresenceofnaturalcarboncyclevariability
AT johnworden detectionoffossilfuelemissiontrendsinthepresenceofnaturalcarboncyclevariability